allen



e. w. ALLEN. A PNEUMATIC CLEANER.

APPUCA HON FILED SEPT- H. 1914- 1,326,901, Patented Jan. 6, 1920.

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PNEUMATIC CLEANER.

APPLICATION FILED SEPT-81,1914.

1,326,901 Patented Jan. 6, 1920.

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'QWM UM e. w. ALLEN. PNEUMATIC CLEANER.

APPLICAHON HLEU SEN-11,1914.

1,326,901. Patented Jan. 6,1920.

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UNITED srATEs PATENT oEErcE.

GEORGE W. ALLEN, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO B. F. STURTEVANT COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

PNEUMATIC CLEANER.

Specification of Letters Patent.

Patented Jan. 6, 1920.

To all whom it may concern:

Be it known that I, GEORGE W. ALLEN, a citizen of the United States, residing at Hyde Park, Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Pneumatic Cleaners; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The present invention relates to pneumatic cleaners and more particularly dust-collectors which are designed for use with such cleaners.

The object of the invention is to improve and reorganize the construction of pneu matic cleaners and dustcollectors, and particularly to arrange the dust bag so that it will automatically be cleared of dust.

WVith the above object in view the present invention consists in the combination and dust-collector hereinafter described and particularly pointed out in the claims.

In the drawings which illustrate the preferred embodiment of the present invention, Figure l is a side elevation, taken partly in section of the multistage blower; Fig. 2 is a front elevation of one of the sheet metal partition plates; Fig. 3 is a section along the line 33 of Fig. 2; Fig. 4 is a front elevation of one of the intermediate blower casings; Fig. 5 is a section along the line 55 of Fig. 4; Fig. 6 is a front elevation of one of the fans or runners; Fig. 7 is a section along the line 7-7 of Fig. 6; Fig. 8 is an elevation taken partly in section of a single screen dust collector; Fig. 9 is an elevation taken at right angles to Fig. 8; Fig. 10 is a plan view of the dust-collector shown in Fig. 8; Figs. 11 and 12 are fragmentary views, being vertical and horizontal sections respectively, of the dust-bag ring fastening device of the collector shown in Fig. 8; Figs. 13, 14, 15 and 16 illustrate the construction for supporting the mouth ring of the dust bag, Fig. 13 being an elevation, Fig. 14 cross section on the line 1414 of Fig. 15; Fig. 15 a cross section on the line 15-15 of Fig. 13; and Fig. 16 a fragmentary sectional view on line 1616 of Fig. 15.

The present invention is illustrated as embodied in the blower and the dust collector of a pneumatic cleaning system of the stationary type in which the blower and dustcollector are mounted separately. The blower is connected through suitable suction connection to the dust-collector and the dust collector is connected to a suction piping system in the building. The suction piping system is provided with suitable intakes to which flexible hose may be attached in the rooms to be cleaned, as will readily be understood by those skilled in this art.

The blower 1 is of the multistage horizontal type and is driven by an electric motor 2 mounted on the same base 3. The blower is connected through an intake 4 to the dustcollector which removes the dust from the air so that clean air passes through the blower. The blower discharges the air through the exhaust passage 5 into the room, or if desired into a connection to out-of doors.

The blower comprises ten fans or runners 10, keyed to a common shaft 11 and inclosed in a fan casing 12. The fan casing is built up of a plurality of sections or single casings. These sections or casings are the inlet casing or section 13, nine intermediate casings or sections 14, and the discharge casing or section 15. Between these sections are placed fiat sheet metal partition plates 16- which cooperate with the sections to form the fan chambers and the fan intake or discharge passages.

The shaft 11 is supported in bearings 20 and 21 in the inlet and exhaust casings respectively. The stuffing-boxes 22 form substantially air and dust tight joints around the shaft.

The intermediate casings 13 each have the outline of a short cylinder, the outer periphery of which is a smooth unbroken cylindrical surface. The inlet and discharge casings also each have substantially the outline of a short cylinder except for the inlet and exhaust connections 4 and 5 and the legs 25. The smooth cylindrical exterior surface thus given to the blower greatly conduces to its attractive appearance and leaves no holes or crevices to catch and hold dust or dirt. The inlet, intermediate and discharge casings are all made of castings, preferably iron. The rear face of the inlet casing 13 is ground flat, the front and rear faces of the intermediate casings 14 are ground flat and parallel. and the front face of the discharge casing 15 is ground flat. When the blower casing is assembled, the fiat sheet iron partition plates 16 are placed between the casing sections fitting against and between the ground fiat surfaces. The entire casing is therefore built up of a number of layers or laminae which are fitted fiat against each other, so that the fitting and assembling of the Various parts is done easily and cheaply. The sections are held assembled by means of six tie rods or bolts 26 which extend through alined holes through the inlet, intermediate and exhaust casings and through the sheet metal partition plates. The ends of the rods 26 are threaded and bear nuts 27 so that the whole casing is held together rigidly. The fit between the flat end surfaces of the castings forming the casings and the edges of the sheet metal partition plates is substantially air tight when the parts are drawn together by means of the tie rods 26.

The inlet casing 13 consists of an exterior w thin annular ring shell 30 and a circular web 31 which forms the front end of the blower casing. Formed on the web 31 are a number of lugs 32 which fit against and serve as a support for the central part of the adjacent partition plate 16. The inlet casing forms a circular chamber into the top of which the air passes from the inlet connection 4 and from the middle of which the air passes to the eye of the first fan.

The construction of the intermediate casings 14 is illustrated in detail in Figs. 4 and 5. Each intermediate casing consists of a thin annular shell or ring 40 and an interior substantially fiat circular web 41. The web 41 forms a partition substantially closing the inside of the intermediate casing with the exception of the hole 42 for the fan shaft 11 and a plurality of air passages 43 which are left through the web 41 where it joins the inside of the ring 40. The front side of the web has a dished central portion 44 which forms a chamber 45 for one of the fans or runners 10, the front wall of the fan chamber being formed by an adj acent partition plate 16. O11 the front face of the web 41 around the periphery of the fan are formed a number of vanes 46 which extend radially and tangentially in a general spiral direction from the periphery of the fan to the outer ring-like shell 40 of the intermediate section forming open-sided air passages 47. The adjacent partition plate 16 fits against the tops of these vanes so as to close the open sides of the air passages 47. The portion 48 of the web 41 which forms the rear walls of these air passages is deflected rearwardly so that the passages 47 are divergent, not only because of the divergence of the vanes 46 but also because of the divergence between the partition plate 16 and the deflected portion 48 of the web 41. The air passages 47 form diffusers for the fan which serve to increase its efficiency as will be understood by those skilled in this art. The air passes from the passages or diffusers 47 through the passages 43 to the other side of the web 41. On the opposite side of the web 41 are formed a number of inwardly directed vanes 50 which extend radially and tangentially inward in a general spiral direction to, form between them open-sided air passages 51. The adjacent partition plate 16 contacts with the tops of the vanes to close the open sides of the air passages 51. The air passages 51 receive the air from the passages 43 and conduct it to the center of the next fan. The diffuser passages 47 receive the air which is discharged at the periphery of the fan flowing in a substantial tangential direction, check its velocity, changing velocity energy into pressure energy, and delivering the air to the passages 43 from which the air flows into the passages 51 which gradually change the direction of movement of the air from tangential to radial and discharge it flowing substantially radially inward at the center of the next fan. The holes through which the tie-rods 26 pass through the intermediate section are indicated at 52 and are formed through the bases of the vanes 46. This disposition of the holes allows the periphery of the sections to be smooth and unbroken and at the same time places the holes where the metal surrounding them does not form undesirable obstructions in the air passages.

The discharge casing 15, like the inlet casing, has a substantially ring-like peripheral portion 60 and a web portion 61 which forms the end closure for the blower. The casing 15 is also provided with a web 62, the front face of which is dished to form the fan chamber for the last fan of the series and upon which, beyond the periphery of the fan, are formed diffuser vanes like the vanes 46 of the intermediate casings. Air passages 43, like the air passages 43 of the intermediate casings, conduct the air through the web 62 and discharge it into theannular space between the webs 61 and 62 from which the air is discharged to the outlet, 5.

One of the partition plates 16 is shown in Figs. 2 and 3, and consists of a disk of fiat sheet iron through which are formed the hole for the fan shaft 11 and the holes 66 for the tie-rods 26.

One of the fans or runners 10 is shown in Figs. 6 and 7. The fan is formed of a single cored aluminum casting. The fan 10 has an elongated hub 70 which is splined to the shaft 11. At the rear of the hub is an outwardly extending circular plate71. In front of the plate 71 and spaced a. little from it is a fiat annular plate 72. A number of fan blades 73 divide the space between the plates 71 and 72 into air passages 74 through which the air is thrown centrifugally by the rotation of the fan, the direction of which is indicated by the arrow in Fig. 6. At the inner edge of the plate 72 is a short axially-extending annular lip 7 5 which fits through the hole in the adjacent partition plate 16. The air after it is delivered by the vanes 50 at the center of the fan flows axially through the eye of the fan which is formed about the hub and is thrown centrifugally outward by the fan blades 73 and discharged into the diffu ers 47.

The blower herein described is very economical to manufacture. All of the joints between the sections are flat so that the only machining necessary to insure a tight joint between the sections is an accurate flat grinding or finishing of the section ends. The sheet metal partition plates 16 are very cheap to make and they fit between the adjacent finished edges of the castings forming substantially air tight joints. As shown in Fig. 1, the edges of the partition plates extend to the peripheries of the castings. The tops of the vanes 16 and 50 fit against opposite sides of the partition plates 16 and securely brace them. The bolt holes and the holes for the passage of the drive shaft can be located in the castings and plates by means of templets.

The parts of the blower can all be standardized, and the blower can be easily and quickly assembled by putting the previously machined and standardized parts together layer by layer and clamping them in assembled position by means of the tie-rods 26. Conversely the blower can be readily disassembled for inspection or repairs.

The dust-collector illustrated in Figs. 8 to 12 comprises a cast iron base 101 in which is received a dust drawer 102, and a dust bag drum 103 mounted on the top of the base and containing the filtering device or fabric dust-bag 104. The dust-bag 10 1 is vertically disposed having an open mouth at its lower end located directly above the dust drawer 102 so that the dust falls from the bag directly into the drawer 102 and may be removed by taking out the drawer. The dust laden air enters the collector through an intake 105 and the air after passing through the dust bag is drawn out by the exhaust blower through the outlet 106. Mounted within the dust-bag drum is a deflector 110. The lower part of the deflector is somewhat smaller than the dust drum so as to leave an annular space between it and the dust drum, while the upper part of the deflector is outwardly flared and joined with an air tight connection 111 to the dust drum, the connection 111 serving to support the deflector within the dust drum. The mouth of the dust bag is secured in the open lower end of the deflector 110 as follows. The lower end of the dust bag is secured to a mouth ring 112 by means of a binding wire 113. The mouth ring 112 is removably secured to the bottom of the deflector by means of three clips 114. The clips 114E consist of arms 115 riveted to the deflector 110 and having at their lower ends inwardly projecting fingers 116 provided with clamping screws 117. The mouth ring 112 is provided with laterally extending lugs 118 which engage over the fingers 116 and are clamped by the screws 117. The mouth ring is placed against the bottom of the deflector 110 and then turned to bring the lugs 118 into position shown in Fig. 12, where they are clamped by means of the screw 117. A felt washer 119 makes a dusttight connection between the mouth ring and the end of the deflector 110. Two cross arms 120 extend across the opening through the mouth ring and prevent the bag from falling down into the dust-drawer. The deflector 110 serves to reduce the velocity of the air entering through the inlet 105 and distribute it uniformly so as not to stir up the dust in the dust drawer.

The air entering through the inlet 105 passes around the annular space between the deflector 110 and the drum 103 and has its velocity gradually reduced by contact with the slower moving air and with the walls so that when the air reaches the lower end of the deflector it forms a circularlymoving comparatively slow air current which is distributed around the periphery of the lower end of the deflector. The air then flows inwardly across the lower end of the deflector and upwardly into the mouth of the dust bag.

This distribution of air current around the entire month of the dust bag serves to prevent the air current from being concentrated in any one place and blowing down into the dust drawer and stirring up the dust therein. Since the air current entering the dust bag is thus distributed around the periphery of the deflector 110, the movement of the air is substantially confined to the upper part of the dust drawer and does not stir up the dust in the drawer.

The outlet 106 passes through the side of the drum 103 above the deflector 110. A deflector plate 130 is joined at its side edges to the inside of the drum 103 and at its bottom edge to the deflector 110, so as to form an air passage having its mouth near the top of the dust bag chamber formed within the drum 103. The air is therefore drawn upwardly through the dust-bag 101 and serves to hold the dust-bag in the inflated position shown in Fig. 8. It is to be noted that the dust bag is secured only at its mouth so that its upper end floats on the air current and its filtering surface is free to be shaken with the fluctuations of the air current.

A wire stiffening screen 131 is secured to the end of the dust bag and serves to hold the end of the dust bag distended. The stiffening screen is made of circular pieces of coarse wire netting and is secured at its edges to the corners of the dust bag. The screen 131 also imparts additional weight to the top of the dust bag to insure a downward movement of the dust bag top in case of a decrease in the air pressure in the dust bag. When the dust collector is in use the current of air serves to inflate the dust bag as shown in Figs. 8 and 9. This weight has especial utility in those cases where the bag is formed of stiff fabric causing it to break when the air pressure is substantially diminished and in consequence thoroughly shaking out the dust which impregnates the walls of the bag.

When the cleaning tools are used, the amount of air which enters the tools and passes through the apparatus varies as the tools are moved over the floor or other surfaces to be cleaned. The fluctuations in the admission of air cause corresponding fluctuations in the pressure exerted by the air in the dust bag and, consequently, cause corresponding movements of the air inflated dust bag, the bag tending to collapse lengthwise and its top to fall toward the open bottom or mouth on a decrease in pressure. Moreover, by virtue of the construction of the blower, when the air intake is closed, or for any reason the amount of air is greatly re stricted, rapid and intermittent fluctuations in the pressure of the air are produced. In the specilic embodiment of the present invention illustrated in the drawings these fluctuations are caused or augmented by the diffuser vanes 46. These fluctuations in pressure act like rapid puffs of air and serve to shake the dust bag. Whenever the cleaning tools are removed and the inlet air cocks are closed while the blower is running, the blower, by virtue of these intermittent puffs of air will serve to automatically keep the dust bag clean. The dust which is shaken from the bag falls directly into the dust bag drawer, 102.

Access to the top of the dust bag drum 103 is had by means of a removable cover 140, which is clamped in place by means of swing bolts 14:1. 7

In the construction illustrated in Figs. 13 to 16, the dust collector has a cast iron base 200 supported on legs 201. Riveted to the top of the base 200'is a dust bag drum 202. Removably secured to the bottom of the baseis the dust box 203. The dust bag drum 202 is a vertical sheet metal cylinder closed at its top and having an outlet 204, the top of which is connected with the intake of the blower. The base 200 has a substantially cylindrical body portion 205 surmounted by a conical or flared portion 206 to which the dust bag drum 202 is attached. The bottom of the base 200 is finished to receive the dust box 203, The dust box 203 is a sheet metal box having a cast metal rim 207. Secured to the rim 207 are two swing bolts 208 which are received in bifurcated ears 209. A felt gasket 210 makes a dust tight joint between the dust box and the base. There is a small clearance between the bottom of the dust box and the floor upon which the dust collector is mounted so that the dust box is easily drawn out when the swing bolts 208 are released. The air intake 211 enters tangentially through the cylindrical portion 205 of the base. The tangential direction of the inlet serves to cause the air to flow in a spiral direction and tends to prevent the air from blowing directly into the dust box and stirring up the dust therein.

The dust bag 220 within the dust bag drum 200 is vertically disposed and has a downwardly opening mouth. The dust bag is made of the usual dust filtering fabric.

Fastened to the upper end or top of the dust a bag is a circular stiffening device 221 made of coarse wire netting. The stiffening device 221 serves the double function of holding the upper end of the dust bag distended and also serves as a weighted means tending to cause the upper end of the dust bag to fall. The upper end of the dust bag is entirely unsupported and is free to rise and fall with the fluctuations of air passing through it. The mouth of the dust bag is secured to a mouth ring 222 by means of a binding wire 223. The mouth ring is circular and of substantially L-shaped cross section, having a cylindrical rim or collar 224C to which the dust bag is bound and an outwardly extending flange 225. On the inside of the base 200 is an inwardly extending annular flange or abutment 226. The flange 225 of the mouth ring is held against the bottom of the abutment 226 with a felt washer 227 interposed so as to make a dust and substantially air tight connection between the mouth ring and the dust collector casing. The mouth ring is removably pressed upwardly so that it, with the dust bag, may be removed if necessary. The means for holding the mouth ring in position comprises two extension struts 230. Each extension strut is formed of a rod 231 mounted to turn in ears 232, and threaded on its lower end to receive a sleeve nut 233. The sleeve nut 233 and rod 231 form a turn buckle by means of which the mouth ring is raised and firmly clamped into position. In the sides of the casing base 200 v are buckets 231, the bottoms of which form steps 235 for the lower ends of the extension struts 230. The above described device for removably clamping the mouth ring in position is cheap to manufacture and allows the dust bag to be readily removed. As above explained, the dust bag 220 is shaken by the fluctuations in the air current passing through it and the intermittent puifs of air caused by the blower running when the air intake is closed and consequently the dust bag is automatically cleaned of dust and seldom has to be removed.

While the preferred embodiment of the present invention has been specifically illustrated and described it is to be understood that the present invention is not limited to its preferred embodiment, but may be embodied in other structures within the scope of the invention as set forth in the following claims 1. A pneumatic cleaner having, in combination, a dust collector comprising a casing and a dust bag in the casing having a downwardly opening mouth and having its filtering surface free to be shaken by fluctuations in the air passing through it, and a blower comprising one or more fans having a plurality of difiuser vanes so as to cause fluctuations or puffs in the air when the admission of air is shut off or greatly reduced.

2. A dust collector having, in combination, a dust bag casing having an interior abutment, a dust bag, a mouth ring for the dust bag, and means including an extension strut for holding the dust ring against the abutment.

3. A dust collector having, in combination, a casing having an interior abutment, a dust bag, a mouth ring for the dust bag, and means for holding the mouth ring against the abutment including a plurality of extension struts connected with the mouth ring and serving, when extended, to clamp the mouth ring against the abutment, said casing having steps to receive the ends of the struts.

mouth mounted in said chamber and interposed between the inlet and outlet, said bag being upwardly distensible and having a weight member attached, adapted to cause an abrupt collapse of the bag upon a substantial reduction in air pressure, and a blower attached to the outlet of the casing and operative to move pulsating currents of air through the bag, the Weight on the bag acting automatically to shake the bag as the latter is intermittently inflated by the pulsating current.

5. A dust collector having, in combination, a casing having a dust bag chamber therein, a dust bag having a downwardlyopening mouth secured to the casing having its upper end free to rise and fall with fluctuations in the air current passing therethrough, and weighting means in the upper part of the dust bag to cause it to fall upon a substantial reduction in the air current with suflicient abruptness to shake the dust from the filtering surface of the dust bag.

6. A dust collector having, in combination, a casing provided with a dust bag chamber, a dust bag having a downwardlyopening mouth supported within the casing and having its upper end free to rise and fall with fluctuations inthe air current passing therethrough, and means mounted in the upper end of the dust bag for causing it to collapse abruptly when the air current ceases to pass through the bag.

GEORGE W. ALLEN.

Witnesses:

C. E. Snow, ANNIE G. RICHARDSON. 

